1. Technical Field
The present invention relates to a printing device that prints on recording paper delivered from a paper roll stored inside, and to a roll paper loading mechanism for loading roll paper into the printing device.
2. Related Art
Printing devices equipped with a roll paper loading mechanism include drop-in type printers that have an opening for loading roll paper rendered in the front of the printer so that the user can tilt an access cover that closes this opening forward and drop the roll paper into the printer.
Japan Patent No. 3855591 teaches a roll paper printer that has this type of roll paper loading mechanism. When the roll paper cover that closes the opening for loading roll paper in this printer is tilted forward, a linkage mechanism that supports the roll paper cover also swings forward. A roll paper loading unit into which the roll paper can be dropped with the rotational axis thereof extending transversely is rendered inside the printer.
The roll paper loading unit in Japan Patent No. 3855591 has a bottom, back, front, and left and right side panels, and the gap between the left and right side walls can be adjusted according to the size of the roll paper. The roll paper loading unit has a roll paper holder that can rotate forward in conjunction with operation of the linkage mechanism when the roll paper cover opens. As a result, when the roll paper cover is opened, one of the side walls and part of the bottom panel of the roll paper loading unit also move forward when the front panel part of the roll paper loading unit rotates to the front. The opening for loading roll paper thus actually becomes larger, and there is no need to lift the roll paper over the front panel part when dropping the roll paper inside. The roll paper can therefore be held substantially level when it is dropped in from the front of the printer. The roll paper loading position also moves forward, making loading the roll paper simple.
Holding the roll paper between and by the left and right side walls of the roll paper loading unit to apply side pressure to the paper roll has also been proposed as a means of preventing the roll paper from rising when recording paper is pulled from the paper roll loaded in the roll paper loading unit.
However, because the gap between the left and right side walls narrows to almost the same width as the roll paper when side pressure is applied to the roll paper by the left and right side walls, the opening to the roll paper loading unit also becomes narrow, making loading the roll paper more difficult. More particularly, when as in the printer described in Japan Patent No. 3855591 one of the side walls does not move from inside the printer, positioning the roll paper widthwise can be difficult when loading the paper, and the paper roll can easily collide with the front edge of the stationary side wall when it is dropped in. This makes pushing the roll paper into the loading position difficult. Furthermore, while the one side wall on the roll paper holder side moves forward with the roll paper cover in the printer taught in Japan Patent No. 3855591, it does not move so far that it is exposed on the outside of the printer case. Positioning to this side wall is therefore also not easy, and the roll paper being loaded can easily collide with the front edge of the side wall.